Automatic Vehicle Recognition (AVR) or Automated License Plate Recognition (ALPR) may refer to the detection and recognition of a vehicle by an electronic system. Exemplary uses for AVR or ALPR include, for example, automatic tolling (e.g., electronic toll systems), traffic law enforcement (e.g., red light running systems, speed enforcement systems), searching for vehicles associated with crimes, access control systems, and facility access control. AVR systems in use today may include systems using RFID technology to read an RFID tag attached to a vehicle. ALPR systems may use cameras to capture images of license plates.
Some AVR systems use RFID, although not all vehicles may include RFID tags. Furthermore, some tag readers may have difficulty pinpointing the exact location of an unpowered RFID tag. As such, these tag readers may only detect the presence or absence of a tag in their field of sensitivity, rather than information included in the RFID tags. Some RFID tag readers may only operate at short range, function poorly in the presence of metal, and/or may be blocked by interference when many tagged objects are present.
ALPR systems use an image capture device to read information of a vehicle, such as a license plate number or other visual content of the license plate. In some instances, the information is attached to, printed on, or adjacent to a license plate. ALPR systems may be used in many environments, since almost all areas of the world require that vehicles have license plates with visually identifiable information thereon. However, image capture and recognition of license plate information for a vehicle may be complex. For example, the read accuracy from an ALPR system may be dependent on the quality of the captured image as assessed by the reader.